The effects of mechanical trapping of cells into the concave micro-grooves on the cell nucleus and differentiation of the vascular smooth muscle cells.

Abstract

Vascular smooth muscle cells (VSMCs) in arterial walls in vivo have contractile phenotype with an elongated shape and significant alignment to the circumference of the arterial wall. On the other hand, VSMCs spread randomly and form irregular shapes during cultivation on a rigid dish, and dedifferentiated to synthetic phenotype. To clarify the mechanisms of such morphological and phenotypic changes in vascular smooth muscle cells, it is essential to develop a cell culture model that consider the mechanical environment of aortic tissue. In this study, we fabricated silicone rubber (PDMS) micro-grooved substrates with three different groove widths (5, 10, 20 μm) using microfabrication technology to promote cell elongation and alignment, and optimized the groove size to improve contractile differentiation. We found that VSMCs adhering into the concaves of grooves allowed remarkable elongation of the cell nucleus and the 5 μm micro-grooved substrates significantly suppressed cell proliferation and promoted vascular smooth muscle cells differentiation.